feat: WoT-weighted content reporting (NIP-56)

[Priyanshubhartistm]

Is your feature request related to a problem? Please describe.

nostream has no support for NIP-56 content reporting today kind-1984 , report events land in the generic DefaultEventStrategy like any other unrecognized kind, with no dedicated handling, storage, or scoring. The NIP-56 spec itself warns against automated moderation driven by public reports, since they're easily gamed by a coordinated handful of accounts.

Describe the solution you'd like

• Accept and store kind-1984 report events where users flag content or pubkeys with standard report types (spam, nudity, illegal, impersonation, etc.)
• Weight incoming reports by the reporter's Web of Trust distance from the operator's seed pubkeys (reuses the distance-lookup API added in
  feat: Web of Trust graph service #626) a report from a direct follow or trusted moderator carries real weight, a report from an unknown pubkey is stored but doesn't trigger anything
• Operators configure a set of trusted moderator pubkeys whose reports can trigger automatic actions (hiding content, deprioritizing in queries); reports from outside that trust circle are surfaced for manual review only
• Reports should be queryable via standard REQ filters so they're visible without needing a dedicated dashboard
• Tests for report ingestion, weighted scoring, and trust-gated action triggers

Additional context

Depends on the WoT graph's distance-lookup API (#626).
This issue only covers ingestion, scoring, and trust-gated actions.